Use this command to create a failover group consisting of two Oracle® Traffic Director instances grouped by a unique virtual IP address (VIP), to provide high availability in active-passive mode. Requests are received at the specified VIP address and routed to the Oracle® Traffic Director instance that is designated as the primary instance. If the primary instance is not reachable, requests are routed to the backup instance.

For active-active failover, you should create two failover groups, both consisting of the same two nodes, but with the primary and backup roles reversed. Each instance is the primary instance for one VIP address and the backup for the other VIP.

There can be a maximum of 255 failover groups, across configurations.

When creating a failover group, if the administration node process is running as non-root on the node where the instances are located, then you must run start-failover on those nodes as a root user. This is to manually start the failover. If this command is not executed, failover will not start and there will be no high availability.

The name of the configuration for which you want to create a failover group.

--virtual-ip|-i

A unique virtual IP address (VIP) to identify the failover group.

The VIP can be a host name or an IPv4/IPv6 address. The VIP should belong to the same subnet as that of the nodes in the failover group, and must be accessible to clients.

--network-prefix-length|-z

The network prefix of the interface on which the VIP should be managed.

The network prefix is the subnet mask represented in the Classless Inter-Domain Routing (CIDR) format. For example, for an IPv4 VIP address in a subnet that contains 256 addresses (8 bits), the CIDR notation of the subnet mask 255.255.255.0 would be 24, which is derived by deducting the number of addresses in the given subnet (8 bits) from the maximum number of IPv4 addresses possible (32 bits).

To calculate the CIDR notation of the subnet mask for an IPv6 subnet, deduct the bit-size of the subnet's address space from 128 bits, which is the maximum number of IPv6 addresses possible.

If you do not specify the network prefix, the default of 24 is assumed for an IPv4 VIP, and 64 for an IPv6 VIP.

--primary-node|-n, --backup-node|-b

The administration nodes that you want to specify as the primary and backup nodes in the failover group. Both the nodes should be in the same subnet and should be running as the root user. The nodes should not have an instance that is already part of another failover group. Note that the administration nodes that you select need not have Oracle® Traffic Director instances running on them.

--force|-f

Specify this option to force creation of the failover group even if a failover group already exists with the specified VIP. The existing failover group will be replaced.

--primary-nic|-m, --backup-nic|-k

The network interfaces, on the primary and back up node, on which the VIP must be managed. If you do not specify the network interfaces, Oracle® Traffic Director discovers them automatically.

--router-id|-r

The router ID for the failover group. The value should be unique across failover groups. If you do not specify the router ID, it is set to 255 for the first failover group. For every subsequent failover group that you create, the default router ID is decremented by one: 254, 253, and so on.